POLAR S725 - Manual (Page 95)

G. PRECAUTIONS
G 93
Using the Polar heart rate monitor in a water environment
Your Polar heart rate monitor is water resistant to 30 meters/ 100 feet. To
maintain the water resistance, do not operate the buttons of the wrist unit
under water.
Users measuring their heart rate in water may experience interference for
the following reasons:
• Pool water with a high chlorine content and seawater are very
conductive. The electrodes of a Polar transmitter may short circuit, which
prevents the transmitter unit from detecting ECG signals.
• Jumping into water or strenuous muscle movement during competitive
swimming may cause water resistance that shifts the transmitter on the
body to a location where it is not possible to pick up an ECG signal.
• ECG signal strength is individual and also varies depending on an
individual’s tissue composition. The percentage of people who have
problems measuring their heart rate is considerably higher in water than
in other environments.